The present invention relates to a tool for installing flexible impellers in water pumps, particularly raw water pumps in marine applications. Typically, these impellers are installed by hand which requires pressing the impeller against the cam surface that is formed on an upper side of the impeller cavity wall in the water pump while concurrently rotating the impeller into alignment with the water pump drive shaft such that the key, serrations, flat surface(s) or other keying means on the impeller hub is aligned with the corresponding groove or other keying means on the water pump drive shaft. The impeller is then urged downwardly onto the shaft while being rotated with the shaft and against the stationary cam and cavity wall so as to uniformly deform and align the impeller blades within the impeller cavity. The impeller is then pressed to the bottom of the cavity for rotation therein with the impeller blades uniformly pressing against the impeller cavity wall. This task can be somewhat difficult when conducted on a work bench, but is extremely difficult when the pump is mounted on an engine where both view of the water pump and access thereto can be extremely limited. Installation is made even more difficult in larger pump applications where the impeller blades are thicker and more rigid and thus more difficult to bend into place.
As a result of the difficulty in installing these impellers, tools such as screw drivers have also been used to help force the impeller into place. However, the use of such devices can easily damage the impeller. It would be highly desirable to provide a tool that facilitated the installation of flexible impellers on water pumps and did so in a manner that would not risk the integrity of the impeller. The present invention provides such a tool.